Incorporating neighborhood context into developmental research may be particularly critical for the study of antisocial behavior. Sociologists have discovered that juvenile crime tends to be clustered in urban areas characterized by widespread poverty (i.e., underclass neighborhoods). However, little research has been devoted to understanding neighborhood effects on the development of antisocial behavior among individual children and adolescents, particularly young children. In the proposed study, neighborhood influences on risk of conduct problems among 284 boys from low-income families will be examined longitudinally, from ages 1 to 6, to control for family-level socio-demographic and psychological functioning characteristics that might account for both the type of neighborhood to which families move as well as risk of conduct problems. This design will permit neighborhood effects to be tested quasi-experimentally by examining changes in child behavior as a function of changes in neighborhood. Questionnaire measures of family socio-demographic characteristics, parental criminality, maternal depressive symptoms, and child conduct problems will be employed, as well as both observational and questionnaire measures of maternal parenting. Neighborhood context will be assessed using census data, subsidized housing locations, and official rates of crime by census tract. It is hypothesized that family poverty, low-SES, single-parent family structure, history of parental criminality, and the presence of maternal depressive symptoms will be associated with an increased probability of moving into underclass neighborhoods. It is expected that living in underclass neighborhoods will be predictive of elevated conduct problems among 5- and 6-year-old boys, controlling for significant family-level selection factors and previous child behavior. Maternal parenting characterized by tight, non-hostile control (even if restrictive) might serve as a protective factor for boys living in these neighborhoods by decreasing their exposure to antisocial influences. Evidence for this hypothesis will be contrasted with an alternative model that posits underclass neighborhood context as a disrupter of parenting quality. This research may have important implications for the development of prevention and intervention efforts aimed at promoting adaptive parenting practices among families living in diverse neighborhood contexts.